Sorting pulp



Aug. 13, 1929. MARTYN SORTING PULP Filed Dec. 24, 1926 M/ v w r0 2 Patented Aug. 13, 1929.

UNITED STATES PATENT OFFICE.

THOMAS GRAHAM MARTYN, DECEASED, LATE OF FORDSBURG, JOHANNESBURG, SOUTH AFRICA; BY GER'IRUDE ELLEN MAETYN, EXECU'TRIX, OF FORDSBURG, JOHANNES- BURG, SOUTH AFRICA.

SOBTING PULP.

continuously stratified in suspension by in jecting hydraulic water into the pulp from below, so that the lighter material is above and the heavier material below. The strata thus formed are continuously withdrawn separately and in succession from the lightest to the heaviest, thus eliminating the tendency for the heavier grades to entrain lighter particles with them.

By hydraulic water is meant clean fluid injected into the pulp so as to effect a separation of the solid particles according to their gravitational resistance to trans portation by such fluid.

If close sorting is desired, the stratified pulp is treated progressively from the light est to the heaviest for final sorting and withdrawal by upward currents of progressively increasing velocities.

It is preferred thus to produce a greater number of final products than is ultimately required in order that the change from one step to another of the final sorting shall be small, resulting in minimum disturbance of the even flow of the pulp and thus leading to cleaner sorting. The products are reunited in any combinations suitable for the further operation, such as vanning, to which the pulp is to be subjected.

Fig. I is a longitudinal vertical section through the apparatus, drawn to an enlarged scale.

Fig. II is a section on III-III Fig, I. Fig. III is a section on IVIV Fig. I.

Fig. IV is a section on V-V Fig. I.

Figs. V and VI are sectional views, at right angles to one another, illustrating duplication of the sorting tubes hereafter described.

2 indicates a slime separating device which delivers clean sand pulp through the slot 3 (Fig. I) to one end of the sorting apparatus 4:.

The latter comprises a box providing an elongated stratifying chamber 5. This may incline somewhat upwards for the reason hereinafter mentioned; but essentially the chamber extends horizontally rather than vertically. The vertical cross section of the chamber is of V form as seen in Figs. II

156,969, and in South Africa January 7, 1,926.

and III; and hydraulic water is admitted at the point of the V, and throughout substantially the whole length of the chamber for the purpose of maintaining the pulp in suspension with its lighter constituents above and its heavier constituents below.

The hydraulic water is fed by perforated pipes *1" having regulating valves 8, to a supply chamber 9 beneath the chamber 5, and passes into said chamber 5 through orifices 10. It is a desideratum that the water should be fed in the form of an unbroken thin sheet; and this form is approximated to, without the mechanical diilicuities result ing from a very narrow slot, by forming the orifices 10 in pairs inclined inwardly towards one another so that their jets impinge and flatten out.

its part of its sorting function, the hydraulic water is required to convey the heavier sand constituents forward in the chamber 5, that is from the feed end 3 towards the end 6. With this object the hydraulic water is given a forward direction by inclining the orifices 10 and also by means of baffles 11, the rear faces of which are in clined similarly to the orifices 10. These bafiles also function to prevent the return of heavy particles as hereafter described. As the transportation of the pulp is completed at the end 6 of the box the last few orifices,

indicated by 10, are not inclined forwardly.

Provision is made for regulating the total quantity of hydraulic water admitted to the chamber 5 and also to differentiate the admission along the length of said chamber; it being usually necessary to admit more to wards the end 3 at which the pulp is fed in than towards the other end 6. With this object a pair of flat faced bars 12, sliding on the flat external surfaces 13 of the lower end of the chamber, are arranged to cover the orifices 10 as desired. Towards each end, a yoke 14 engages the bars 12 by set-screws 15 and is connected to a rod 16 which is raised and lowered by a hand wheel nut 17. The rod passes through a stuffing box 18 which is protected from sand by a rubber sleeve 19. It will be seen that by raising or lowering both rods 16 equally, all the orifices 10 are equally opened or closed; and that by raising o1- lowering one rod more than the other, the orifices 10 towards one end are opened or closed more than those towards the other end. It is preferred however to leave the first pair of orifices, indicated by 10", always fully open, in order to ensure the pulp from the slot 3 being kept properly in suspension. To kee the bars 12 in close contact with the sur ace 13, the yokes 1e are arranged as springs pressing said bars inwards; and similarly acting springs are arranged at intervals.

The hydraulic Water, acting on the incoming pulp at the feed end of the chamber 5, roughly classifies the same vertically, the lighter particles being suspended on the Whole in the higher and wider part of the l! section of thechamber 5 and the heavier particles tending to occupyprogressively lower positions. The strata thus formed are continuously withdrawn from the upper part of 'ority according to their lightness.

means which takes them in the order of pri- The means shown for this purpose also effects the further and more precise sorting of the particlesand-consists of a series of sorting tubes 2l 21 These tubes are individually vertical or substantially so, and are arranged in a series extending longitudinally of the box, the lighter grades being separated by the earlier tubes 2121 etc. and the heavier grades by the later tubes towards 2l 2l.

' The stratified pulp is first presented to the sorting tube'21 the current in which is such as to carry up through said tube only the lightest particles of sand, heavier particles falling back into the chamber 5.

The section of the chamber 5 beneath the next tube 21 being rather smaller than that beneath 21 owing to the narrowing form of the chamber, the pulp offered to this tube is on the whole somewhat coarser or heavier than that presented-to tube 21. The current velocity in the tube 21 is made correspondingly greater than that in tube 21 so tl it a heavler grade 1s carried up through, and discharged by, this tube. This presentation of progressively heavier pulp in a state of partial classification to tubes capable of carry-- ing off progressively heavier constituents, continues throughout'the series until the heaviest sand is passed oil by the strongest current through the last tube 21.

It Will be seen that the heaviest sand has to be conveyed for the greatest distance along the chamber 5 and for this reason the hydraulic water is given a forward inclination.

In the preferred construction the areas of all the tube outlets 22 are equal, and consequently the varying current velocities are attained by varying the cross sections of the tubes; the tube2l therefore having the greatest cross section and the tube 21 the least. The tubes are preferably contracted towards the top as shown in the cross sections'.

' In order to prevent eddying and return currents in the tubes it is desirable that the 'tube area should not greatly exceed about 41;

square inches. Accordingly if it is desired to enlarge the capacity of the machine for pulp of a. given cmistitution, the increased area is attained by duplicating the tubes as indicated in Figs. V and VI.

In order to obtain pulp products as thick as possible, without necessitating undue hydraulic head to force such thick pulp through the tubes, the tubes are made as short as is consistent with good sorting and. the elevation of the pulp is effected largely by the hydraulic water in the chamber 5.

The tubes for the heavier pulp can be shorter than those for the lighter pulp; and as it is desirable for the outlets 22 i be all on the same level, the top of the chamber 5, that is, on the section VV Fig. I, is somewhat inclined upwards.

The outlets 22 are conveniently all formed in a removable cover 23 which permits access to the interior of the tubes 21, and which can also be readily chai'lged for another having smaller or larger outlets if it is desired to alter the grade produced. Outlets are dupliated at both sides of the cover 233 so that the apps: us can deliv r to either side the duplicate outlets which are not required be ing plugged as indicated at 24-.

it is n'eferrcd to orovide a considerably larg r number of sorting tubes 21 than the number of grades of sand ultimately required; the example showing twelve -tubes for three final products. Variation of current i in one tube to the next being thus minim .ed, abrupt changes in the flow and constitution of the pulp are avoided and cleaner separation is obtained.

The tube products are re-unitcd in any suitable combinations conveniently by means of hoses 25 attached to the outlets, several of which can. be brought together to feed each of a series of concentrating tables or the like. The horizontal arrangement of the outlets 22 facilitates this re-uuit ng of the tube products without loss of head.

Tv llllSt the primary function of the balllcs 11 is to direct the hydraulic water forward and with it the hea 'lOl' material, they also function to prevent such heavy material from sliding back along the bottom of the chamber 5, after having been once carried or thrown forward. Such heavy matter tends to accumulate in the pockets 2?) between the bafi'les 11. It is there agitated by the relativruy strong current of hydraulic water which tends to throw it over the forward edge of each pocket into the next forward pocket, and so on through the series of pockets.

The apparatus can readily be cleaned out by fully uncovering the orifices l0 and opening a discharggge outlet 27 provided for the purpose at the lowest part of the apparatus.

The large size out the orifices 1O permits heavy sand, which settles in the pockets 26, to pass through said orifices without difiiculty. VVator for sluicing may be supplied by means of the pipes 7, the perforations of which are at their lower sides to prevent ingress of sand and to facilitate this operation, The cover 23 may be removed if desired and the ap paratus thoroughly washed out with a hose.

I claim 1. Pulp sorting apparatus comprising a single materially horizontal chamber oi? V cross section having a clear opening from end to end so that continuous strata can form in it, means for injecting hydraulic water at the point of the V, said means being arranged to produce, at a short distance above the point of the V, abody of hydraulic water substantially continuous throughout the whole length of the chamber, and means for separately withdrawing, from the upper part or": the chamber, strata of suspended. pulp in succession beginning with the lightest.

2. Pulp sorting apparatus comprising a single chamber disposed to a material extent horizontally, means to feed pulp at one end of the chamber, the chamber being of V cross section and of decreasing cross sectional area away from the feed end, means to feed bydraulic water at the point of the V, said water feeding means being arranged to produce, at a short distance above the point of the V, a body of hydraulic water sul'istantially continuous throughout the length of the chamber, and means at the upper part of the chamber for separately withdrawing strata of suspended. pulp in succession from the lightest to the heaviest.

3. Pulp sorting apparatus comprising a materially horizontal chamber, means to feed pulp to the chamber, means to feed bydraulic water to the lower part of the ch amber substantially throughout its whole length, a mechanism adapted to control sin'iultaneously the inflow of hydraulic water at all points and adiustable to taper the inflow towards either end of the chamber, and means for separately witl'idrawing different grades of pulp from the upper part of the chamber.

4. Pulp sorting apparatus, con'iprising a chamber of V cross section decreasing in crosssectional area towards one end, means to feed pulp into the larger end of the chamber, means to feed hydraulic water at the point of the V for substantially the whole length of the chamber, a mechanism adapted to control simultaneously the inflow oi": hydraulic water at all points and adjustable to taper the inflow towards either end of the chamber, and a graduated series of final sorting devices forming the outlet from the chamber:

Pulp sorting apparatus comprising a chamber of V cross section decreasing in cross-sectional area towards one end, means to feed pulp into the larger end of the chamber, having conveying pairs of passages, means to feed hydraulic water at the point of the V in the form of numerous pairs of jets the oi each. pair iriipinging on one another with a lateral inclination to form an upwardly directed flat sheet, and means for separately withdrawing dili'erent grades of pulp from the upper part of the chamber.

6. Pulp sorting apparatus comprising a chamber oi V cross section decreasing in cross-sectional area towards one end, means to feed pulp into the larger end or the chamber, means having conveying pairs of? passages to teed hydraulic water at the point of the V in the form of numerous pairs of jets the jets of each pair impinging on one another with a lateral inclination to form an upwardly directed fiat sheet,means :tor varying the llow oi? said pairs of etsprogre vely along the length of the chamber, and means for separately withdrawing different grades of pulp from the upper part of the chamber.

7. Pulp sorting apparatus comprising an elongated chamber, means to feed pulp to one end of the chamber, means to feed hydraulic. water into the lower part of the chamber sub-- stantially throughout its length, bullies in the lower part of the chamber forming between thorn pockets and shaped to guide the hydraulic water upwardly and with an inclination away from the feed end of the chamber and a graduated series o't pulp sorting tubes forming the outlet from the upper part of the chamber and closely spaced so that their mouths occupy substantially the whole area of the top of the chamber:

8. Pulp sorting apparatus comprising a chamber of ll cross section, means to teed pulp to 'one end oi the chamber, a. series oi bafiles providing lfietwecn them pointed pockets in the bottom of the V, means to introduce hydraulic water at the point of the ll, with an inclination away from the teed end of the chamber, the battles being sl'ia'ped to assist such inclined flow ot' the hydraulic water, and a graduated series of sorting tubes forming the outlet from the upper part of the chamber and closely spaced so that 'tl'ieir mouths occupy substantially the whole area oi. the top of the chamber.

9. Pulp sorting apparatus comprising an undivided chamber arranged to a material extent horizontally, means to feed pulp to one end of the chamber, means to teed hydraulic water to the lower part of the chamher, and a graduated series of sorting tubes forming the outlet from the upper part of the chamber, said tubes being provided with individual outlets arranged to produce a substantially uniform hydraulic head in all the tubes, the ratio of tube cross sectional area to outlet area being progressively varied to give the tubes progressing varying sorting characteristics.

10. Pulp sorting apparatus comprising an undivided chamber arranged to a material extent horizontally, means to feed pulp to one end of the chamber, means to feed hydraulic water to the'lower part of the chamher, and a graduated series of sorting tubes forming the outlet from the upper part of the chainbe said tubes being provided with individual outlets arranged to produce a substantially uniform hydraulic head in all the tubes, the tubes being of decreasing cross sectional area away from the pulp inlet.

11. Pulp sorti g apparatus comprising an elongated upwardly inclined undivided chamber, means to feed pulp to the lower end of the chamber, the chamber being of V section lHdOl decreasing cross-sectional area towards its upper end, means to feedhydrauhc water at the point of the a sub stantially uninterruptedly throu hout the 1 1 D whole length OI the chamber, a mechanism adapted to control simul aneously the inflow of hydraulic water at all points and ad justable to taper the inflow towards either end of the chamber, and a series of sorting tubes forming the outlet from the upper part of the chain er and closely spaced so that their mouths occupy substantially the Whole area of the top of the chamber and progre sively decreasing in area and length away rrom the feed end of the chamber.

12. The method of sorting pulp according to its tendency to fall in liquid, which consists in forming and continuously maintaining a substantially undivided body of pulp having considerable horizontal extent relatively to depth and considerable length relatively to its width, continuously suspending and stratifying the pulp of such body by means of hydraulic water admitted into it from below and substantially uninterruptedly throughout its length, and separately withdrawing different strata'in the order from the lightest to the heaviest.

18. The method of sorting pulp, which consists in forming and continuously maintaining a substantially undivided body of pulp having considerable horizontal extent relatively to its depth and considerable length relatively to its width, continuously suspending and stratifying the pulp of said body, with the lightest constituents above, by'means of hydraulic water admitted into the pulp from below and substantially uninterruptedly throughout its length, and presenting strata in succession, beginning with the lightest, to a progressive series of upward currents each adjusted for closely sorting the material of a different stratum.

lt. Pulp sorting apparatus, comprising to a material. extent horizontally, means to feed pulp to one end of the chamber, the chamber being of V cross section and of decreasing cross sectional area away from the feed end, means to feed hydraulic water at the point of the V substantially throughout the length of the chamber, and a series of upward flow sorting tubes forming the outlet from the upper part of the chamber and closely spaced so that their mouths occupy substantially the whole area of the top of the chamber, said tubes being graduated tor the production through them of currents increasing in velocity from one end of the series to the other.

15. Pulp sorting apparatus, comprising an uninterrupted chamber disposed to a material extent horizontally, means to feed pulp to one end of the chamber, the chamber being of V cross section and of decreasing cross sectional area away from the feed end, means to feed hydraulic water at the point of the V substantially throughout the length of the chamber, and a series of upward flow sorting tubes forming the outlet from the upper part of the chamber and closely spaced so that their mouths occupy substantially the whole area of the top of the chamber, :iid tubes being graduated for the production through them of currents increasing in velocity from one end of the series to the other, said tubes being of different lengths and having their outlets on a common level.

16. Pulp sorting apparatus comprising an uninterrupted and upwardly sloped chamber of V cross sect-ion and decreasing in cross sectional area from its lower end, means to feed pulp into the lower end of the chamber, means to feed hydraulic water at the point of the V substantially throughout the length of the chamber, and a series of upward flow sorting tubes forming the outlet from the upper part of the chamber and closely spaced so that their mouths occupy substantially the whole area of the top of the chamber, said tubes being graduated tor the production through them of currents increasing in velocity from one end of the series to the other.

In testimony whereof I aflix my signature.

GERTRUDE ELLEN MARTYN, Eazecmrir Testamentary for T71 omas Gin/1am Marty n, Deceased. 

